One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6)(7,8)(9,10)(11,12)(13,14,17,20)(15,16,19,18)(21,22)(23,27)(24,25)(26,28)(6,10)(7,12)(13,14,17,20)(15,16,19,18)(22,25)(26,27)(5,7,9,12)(6,11,10,8)(13,15,17,19)(14,18,20,16)(21,22)(23,26)(24,25)(27,28)(1,2)(3,4)(5,6)(7,11)(8,12)(9,10)(13,14)(15,18)(16,19)(17,20) involution — undirected(5,8,9,11)(6,12,10,7)(13,16,17,18)(14,19,20,15)(21,23)(22,26)(24,28)(25,27)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.